Cut the beef chuck roast into 2-inch chunks, removing the larger pockets of fat as you work.
Add the beef to a large crockpot followed by the garlic powder, dried oregano, kosher salt, dried pasilla peppers, beer, Worcestershire sauce and soy sauce. Stir the ingredients together, cover and cook the beef on low for 8 hours or until the beef is very tender.
After 8 hours, shred the beef with a fork, pull the peppers from their stems (and remove the stems) and stir in the juice from one lime along with another 1-2 teaspoons of kosher salt, depending on your taste. Cover the beef to keep warm while you make the coleslaw that will top the tacos.
Finely slice (or shred) 3 cups of cabbage. Add the cabbage to a large bowl along with the remaining ingredients. Mix well.
To assemble the tacos, place a generous amount of shredded beef on top of softened corn or flour tortillas. (Note: I like to toast my tortillas over a gas burner but softening them up in the microwave or in the oven works too). Top the beef with a spoonful of coleslaw and a dash of hot sauce.
This recipe will serve a crowd, with plenty of leftovers. Enjoy!